Comparison

UCSF Eureka Research vs 99 Days Reset

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

UCSF Eureka Research

Participate in real medical research studies from your smartphone to help solve major health issues. Contribute to world-changing research with top universities and make a significant impact on causes you care about.

Highlights
  • Join medical research studies
  • Contribute to health problem solutions
  • Participate via smartphone
  • Support top research universities
  • Track impact on health causes
Features
Read full description

Eureka makes it easy to join real medical studies and help solve the world’s biggest health problems—including heart disease, diabetes, cancer, mental illness, healthcare inequities and more. It’s now easier than ever to have a big impact on causes you care about . All it takes to contribute to world-changing research with Eureka is a smartphone and a little bit of free time. Team up with millions of other study participants helping top researchers from research universities like UCSF, Harvard, and Johns Hopkins to answer questions like, “What signals from my smartphone might predict heart disease?” and “How does physical activity affect cancer risk?” Eureka is a non-profit resource built by researchers at the University of California, San Francisco with support from the National Institutes of Health. If you have questions about signing up or your current participation, reach out to us at support@eurekaplatform.org. For the studies that are on our app, we are not currently pulling HealthKit data but are collecting approval for future use. We use the CareKit framework in our application but do not connect to it in any other way.

About

99 Days Reset

Features
Read full description

99 Days Reset helps you break free from unwanted habits by removing distractions before they become a problem. Your goal is simple. Stay consistent for 99 days. Check in every day, be honest with yourself, and keep going. The app is designed to help you build better habits and make staying on track easier over time. Features 99 Day Reset Track your progress and stay accountable with a simple daily check in. Always Block Adult Websites Adult websites stay blocked at all times through a carefully designed blocking system that's made to be difficult to bypass. Intentional Mode Block the apps that trigger your habits before they become a problem. Intentional Mode helps eliminate distractions at the source so you rely less on willpower and more on your environment. Failed Mode If you relapse, Failed Mode temporarily locks your selected apps, making it much harder to immediately fall back into old habits. Private by Design Everything stays on your device. No account. No social feed. No public profile. 99 Days Reset is a self improvement tool. It is not therapy or medical treatment.

Screenshots

UCSF Eureka Research4 screens
99 Days Reset4 screens

Verdict

The call

The clearest difference is price: UCSF Eureka Research at Free against 99 Days Reset's $1.99. UCSF Eureka Research also leads on device support (3 vs 1) and iOS requirement (14.0 vs 17.0). 99 Days Reset's advantage is update cadence (fortnightly vs every 5 weeks). On ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

UCSF Eureka Research is free to download; 99 Days Reset costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

UCSF Eureka Research ships an update every 5 weeks, 99 Days Reset fortnightly. The most recent releases landed on October 24, 2026 and October 20, 2026 respectively.

Scorecard4 real differences · 6 level
UCSF Eureka Research versus 99 Days Reset: the parameters behind the verdict, then further details
ParameterUCSF Eureka Research99 Days Reset
PriceFree — better$1.99
Rating3.1 (330 ratings) — better—
Positive reviews22.2% of reviews—
Number of ratings330 — better—
Update frequencyEvery 5 weeksFortnightly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPod, Apple Watch — betteriPhone
Requires iOS14.0 — better17.0
Further details — not scored
Size61 MB2 MB
Age rating17+17+
DeveloperUniversity of California at San Franciscodario demenga

Bugs and requests

UCSF Eureka Research

Reported bugs

4 issues
  • App crashes during data entry
  • Login issues, unable to reset password
  • Incompatible with certain devices (e.g., jailbroken, older devices)
  • Unexpected behavior when trying to opt out or delete account

Requested features

4 requests
  • Improve stability and reliability
  • Provide better instructions and guidance
  • Add support for international users
  • Improve battery optimization

99 Days Reset

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

UCSF Eureka Research

No in-app purchases

None

99 Days Reset

No in-app purchases

Questions

Is UCSF Eureka Research free?
UCSF Eureka Research is free to download, with no in-app purchases.
Is 99 Days Reset free?
99 Days Reset costs $1.99, with no in-app purchases.
Do UCSF Eureka Research or 99 Days Reset have ads?
Neither UCSF Eureka Research nor 99 Days Reset shows ads.
Which is updated more often, UCSF Eureka Research or 99 Days Reset?
UCSF Eureka Research ships an update every 5 weeks, and 99 Days Reset fortnightly. Most recently, UCSF Eureka Research was updated on October 24, 2026 and 99 Days Reset on October 20, 2026.

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