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AndroidAPS

Open-source community (AndroidAPS project)

A mature open-source automated insulin delivery app for Android, built on the OpenAPS/oref algorithm. Among the most advanced and tunable DIY loops — with Super Micro Bolus, automatic sensitivity (Autosens), and dynamic ISF — and the only open-source system whose algorithm has been validated in a published randomized controlled trial.

Available nowStrong evidenceopen-sourcediyandroid

The scorecard

Algorithm sophistication90

OpenAPS/oref1 lineage with Super Micro Bolus, Autosens auto-sensitivity, and dynamic ISF; the CREATE randomized trial showed this algorithm raised time-in-range by 14 percentage points versus a sensor-augmented pump.

Hardware support80

Broad, growing pump roster (Dana, Accu-Chek Insight/Combo, Omnipod DASH/Eros, Medtrum, Diaconn, EOPatch, Equil) plus Dexcom, FreeStyle Libre and Eversense glucose sources — wider than most DIY loops, but Android-only and limited to a specific compatibility list.

Customizability95

Every parameter is inspectable and tunable and the source is fully open — the defining advantage of the system, enabling individualization commercial AID does not allow.

Community & docs88

Large multinational user base (an 897-user survey spanned 35 countries), extensive maintained documentation, and a structured objectives-based onboarding with active community support.

Ease of setup40

Cannot be downloaded ready-made: users must self-compile the app in Android Studio, then progress sequentially through 11 objectives (closed loop and SMB unlock only at objectives 6 and 9, over months) — far more effort than a commercial system.

The full picture

AndroidAPS (AAPS) is a free, open-source automated insulin delivery (AID) app — an "artificial pancreas system" — that runs on Android smartphones and uses an OpenAPS software algorithm to automate insulin dosing.1 There is no iOS version; the open-source iPhone equivalent is the separate Loop app. AAPS pairs a phone, a continuous glucose monitor (CGM), and a compatible insulin pump into a closed loop.1

Algorithm and sophistication. AAPS implements the OpenAPS "oref" algorithm. Its most advanced mode, oref1, adds Super Micro Bolus (SMB) — frequent tiny correction boluses instead of only temporary basal rates — introduced in 2018.2 It also offers Autosens, which infers how sensitive or resistant you currently are from glucose deviations and adjusts basal and ISF accordingly, and DynamicISF, which continuously rescales insulin sensitivity from total daily dose and predicted glucose (needing about five days of data).34 This makes its handling of changing sensitivity and partly-announced or unannounced meals among the most capable of any loop.

Supported hardware. AAPS supports an unusually broad pump list for a DIY system: Dana R/RS/-i, Accu-Chek Insight and Combo, Omnipod DASH and Eros, Medtrum Nano/300U, Diaconn G8, EOPatch2, Equil, and certain older Medtronic models (the last two needing an extra relay device).5 CGM sources include Dexcom (G5/G6/G7), FreeStyle Libre 2/3, and Eversense, mostly routed through the companion xDrip+ app.6

Customizability, community, docs. Because the code is open, every parameter is inspectable and tunable — the defining advantage over commercial AID, which cannot be individualized to the same degree.7 AAPS has thousands of users worldwide; a multinational survey of open-source AID users drew 897 respondents across 35 countries.8 Documentation is extensive and maintained on a public ReadTheDocs site.1

Setup complexity and legal status. AAPS cannot simply be downloaded: for legal and safety reasons users must build (compile) the app themselves in Android Studio.1 After installing, you must complete 11 sequential "objectives" — open loop, low-glucose-suspend, then closed loop and SMB unlock progressively, with SMB at objective 9 — a process that typically takes months.9 The project states plainly that it is for informational/educational use, carries no warranty or manufacturer endorsement, and is used "at your own risk."1 AAPS is not a regulator-approved medical device; in 2019 the U.S. FDA warned against unauthorized diabetes devices, including do-it-yourself automated insulin dosing systems, citing risks of unsafe dosing.10 Responsibility that commercial support would carry falls on the user.

Clinical evidence. Uniquely among DIY loops, the AAPS/OpenAPS algorithm was tested in a randomized controlled trial. The CREATE trial (NEJM, 2022) randomized 97 children and adults to a modified AndroidAPS 2.8 + OpenAPS 0.7.0 system (DANA-i pump, Dexcom G6) versus a sensor-augmented pump; time-in-range rose from 61.2% to 71.2% with AID — an adjusted 14-point benefit (about 3 hours 21 minutes more per day in range), with no severe hypoglycemia or ketoacidosis in either arm.11 A 24-week continuation phase confirmed durable benefit across pump types and ages over 48 weeks.12 Large observational datasets agree: a pediatric survey and a multinational adult/caregiver survey both reported significant HbA1c and time-in-range improvements after starting open-source AID.138

What's coming. Development is continuous and community-driven rather than tied to a release cycle. Recent versions (3.x) have matured DynamicISF and a Full Closed Loop mode that reduces meal announcements, and broadened pump support (e.g. newer Omnipod, Medtrum and Equil patch pumps).35 Because the algorithm is open, advances such as more automatic meal handling typically appear here before commercial systems.

Glucose values: time-in-range target is 70–180 mg/dL (3.9–10.0 mmol/L).

References

  1. AndroidAPS project. Welcome to the AndroidAPS documentation (platform, OpenAPS algorithm, required components, build-it-yourself requirement, and risk/no-warranty disclaimer). AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/index.html ↩ ↩2 ↩3 ↩4 ↩5

  2. AndroidAPS project. OpenAPS features — Super Micro Bolus (SMB), an oref1 feature introduced from 2018. AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/Usage/Open-APS-features.html ↩

  3. AndroidAPS project. DynamicISF (DynISF) — dynamic insulin sensitivity from total daily dose and predicted glucose. AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/DailyLifeWithAaps/DynamicISF.html ↩ ↩2

  4. AndroidAPS project. OpenAPS features — Autosens sensitivity detection. AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/Usage/Open-APS-features.html ↩

  5. AndroidAPS project. Compatible Pumps. AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/Getting-Started/CompatiblePumps.html ↩ ↩2

  6. AndroidAPS project. Compatible CGMs / glucose sources (Dexcom, FreeStyle Libre, Eversense via xDrip+). AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/Getting-Started/CompatiblesCgms.html ↩

  7. Burnside MJ, Lewis DM, Crocket HR, et al. CREATE trial protocol — open-source algorithms allow individualisation of algorithm parameters, unlike commercial AID. J Diabetes Metab Disord (2020). https://pubmed.ncbi.nlm.nih.gov/32837953/ ↩

  8. Braune K, Gajewska KA, Thieffry A, et al. Why #WeAreNotWaiting — motivations and self-reported outcomes among users of open-source AID: multinational survey (897 respondents, 35 countries; HbA1c 7.14%→6.24%, TIR 63.0%→80.3%). J Med Internet Res (2021). https://doi.org/10.2196/25409 ↩ ↩2

  9. AndroidAPS project. Completing the Objectives — 11 sequential objectives; closed loop and SMB unlock progressively. AndroidAPS ReadTheDocs (accessed 2026). https://androidaps.readthedocs.io/en/latest/SettingUpAaps/CompletingTheObjectives.html ↩

  10. U.S. Food and Drug Administration. FDA warns against the use of unauthorized devices for diabetes management (including do-it-yourself automated insulin dosing systems). FDA (2019). https://www.fda.gov/news-events/press-announcements/fda-warns-against-use-unauthorized-devices-diabetes-management ↩

  11. Burnside MJ, Lewis DM, Crocket HR, et al. Open-Source Automated Insulin Delivery in Type 1 Diabetes (CREATE randomized controlled trial). N Engl J Med 2022;387(10):869-881. https://pubmed.ncbi.nlm.nih.gov/36069869/ ↩

  12. Burnside MJ, Lewis DM, Crocket HR, et al. Extended Use of an Open-Source Automated Insulin Delivery System: the 24-week continuation phase following CREATE (48 weeks total; treatment effect +12.2% TIR, no DKA or severe hypoglycemia). Diabetes Technol Ther 2023;25(4):250-259. https://pubmed.ncbi.nlm.nih.gov/36763345/ ↩

  13. Braune K, O'Donnell S, Cleal B, et al. Real-world use of do-it-yourself artificial pancreas systems in children and adolescents: online survey (209 caregivers, 21 countries; HbA1c 6.91%→6.27%, TIR 64.2%→80.7%). JMIR Mhealth Uhealth (2019). https://doi.org/10.2196/14087 ↩