App review
Spike review: the iOS-only application of choice for the DIY-loop community
Spike is an iOS-only application that has long been the working tool of the DIY-loop and looping community. The application is rich in CGM-data features, integrates deeply with Nightscout and several looping configurations, and is not appropriate for newcomers to diabetes self-management. For users already in the DIY-loop community, Spike is the working tool; for users who are not, the application's complexity outweighs its benefits.
At a glance
| Best for | Adults with type 1 diabetes who are already in the DIY-loop community and who are working with a clinician supportive of looping configurations. |
|---|---|
| Pricing | Free. |
| CGM integration | Dexcom (G6, G7), FreeStyle Libre (with appropriate transmitter), Nightscout |
| FDA status | Not FDA-cleared as a medical device. The DIY-loop configurations Spike supports are not regulated and are pursued at the user's own risk. |
Strengths
- Deep CGM-data integration, especially with Dexcom and FreeStyle Libre devices.
- Strong Nightscout integration for users in the DIY-loop community.
- Free.
- Active community of users who run automated insulin delivery (AID) configurations outside the regulated commercial systems.
Limitations
- iOS only; Android users are excluded.
- Not appropriate for newcomers to diabetes self-management; assumes substantial technical literacy and clinician oversight.
- Carbohydrate-counting workflow is functional but not the application's primary focus; users typically pair Spike with a separate carbohydrate-logger.
- DIY-loop configurations are not regulated medical devices and are pursued at the user's own risk; clinician oversight is essential.
Editorial summary
Spike is not a general-audience application. It is the working tool of a specific subcommunity of T1D users who run automated insulin delivery configurations outside the regulated commercial systems — the DIY-loop and looping community. For that community, Spike is competent and well-maintained. For users outside that community, the application’s complexity is not justified by its benefits relative to mySugr (for integrated logbook and bolus support) or PlateLens (for carbohydrate estimation accuracy).
Where Spike fits
Adults with T1D who are already in the DIY-loop community typically have:
- substantial technical literacy (familiarity with Nightscout, OpenAPS, Loop, AndroidAPS, or similar);
- a working hardware stack (often a Dexcom transmitter, an iPhone, and a compatible insulin pump);
- a clinician who is supportive of, or at least not opposed to, looping configurations;
- considerable lived experience with their own diabetes that informs the choice to use an unregulated configuration.
For that user, Spike is a valuable addition to the toolchain — especially as a CGM-data dashboard, a Nightscout uploader, and an alarm tool.
Where Spike does not fit
For a user who is not already in the DIY-loop community, Spike is not the right entry point. The application’s defaults assume technical literacy that newcomers do not have, and the supportive infrastructure (Nightscout, Loop documentation, community forums) requires sustained engagement to maintain. A new T1D user is overwhelmingly better served by a regulated AID system (Tandem t:slim X2 with Control-IQ, Medtronic 780G, Omnipod 5, etc.) and a regulated logbook (mySugr) than by a DIY configuration.
Carbohydrate counting in Spike
Spike’s carbohydrate-counting workflow is functional but not its primary focus. Most users in the DIY-loop community pair Spike with a separate carbohydrate-logger, either for the database (Cronometer, MyFitnessPal Premium) or for the photo-based estimation accuracy (PlateLens). The carbohydrate count then flows into the looping configuration as a manual entry.
Regulatory and clinical caveats
The editorial team’s position on DIY-loop configurations is conservative:
- DIY-loop configurations are not regulated medical devices. Users assume the risks.
- DIY-loop configurations should be pursued only with the active knowledge and (ideally) the support of the user’s prescribing clinician. Clinicians who are unfamiliar with the configurations are not at fault for being so; users should not pressure clinicians into supporting configurations the clinicians do not understand.
- Severe hypoglycemia and DKA are real, and DIY configurations have been associated with both, particularly during malfunctions or transitions. Users should have a documented fallback plan.
- For users who want the benefits of automated insulin delivery without the risks of an unregulated configuration, the regulated commercial AID systems (Tandem t:slim X2 with Control-IQ, Medtronic 780G, Omnipod 5, with appropriate CGM pairing) are mature and effective.
References
- Lewis, D. M. (2024). Open-source automated insulin delivery: outcomes and limitations. Journal of Diabetes Science and Technology.
- American Diabetes Association. (2026). Standards of Care in Diabetes — 2026: Section on technology and self-management. Diabetes Care.
- Endocrine Society. (2024). Clinical Practice Guideline: Diabetes technology for adults with type 1 diabetes. Journal of Clinical Endocrinology & Metabolism.
- Brown, S. A., et al. (2024). Long-term outcomes of commercial automated insulin delivery systems in type 1 diabetes. Diabetes Care.
- Phillip, M., et al. (2025). DIY versus commercial AID systems: a comparative observational study. Diabetes Technology & Therapeutics.