Stim Check

Stim Check helps you monitor how much caffeine remains active in your body so you can plan workouts, naps, and evening routines more intelligently. This compact utility makes it easy to log coffee, pre-workout, or energy drinks and then see an immediate, science-based estimate of active caffeine over time. You will find a clear-by time showing when stimulant levels fall below a sleep-safe threshold and an at-a-glance visual timeline to guide same-day decisions about training, rest, and late-afternoon consumption.

Key features and measurements

Stim Check calculates a real-time caffeine curve that visualizes decay after each logged serving, using basic pharmacokinetic principles tailored to your input. The app accepts common beverage types and concentrations, allows quick quantity selection, and computes active caffeine using your body weight and a configurable caffeine half-life parameter. Results are presented as an easy-to-read curve with precise numeric readouts for current active milligrams and a projected time when levels will be low enough to minimize sleep disruption. The tool emphasizes clarity over noise: entries and edits are fast, and the main view focuses on the next several hours so you can immediately judge whether a workout or nap is a good idea.

User interaction and controls

Controls are designed for quick, repeatable actions. Logging a drink takes only a few taps: choose a beverage category, select an approximate serving size, and confirm. Adjustment controls let you refine caffeine content per serving or set a custom half-life if you and your clinician prefer a different baseline. A timeline slider or scrubber lets you inspect past entries and future projections; tapping any point on the curve shows the estimated active caffeine at that moment and the contributing entries. Entry history is editable to correct amounts or times, and gesture-friendly navigation keeps common tasks one or two actions away.

Progression, trends, and daily patterns

Although Stim Check is a lightweight utility rather than a full analytics suite, regular use reveals patterns: typical peak windows, times when intake tends to push clear-by times later, and how dose size affects sleep risk. Over days and weeks you can observe habitual timing, which supports better personal decisions about training intensity and nap scheduling. The app’s simple history view makes it easy to compare recent days and to learn whether adjustments like smaller afternoon servings lead to earlier clear-by times.

Visual style and accessibility

The interface prioritizes a single, readable caffeine curve with color cues and day/night background shading to place activity in a 24-hour context. Text contrast and font sizes are chosen for legibility, and labels are concise to reduce clutter. Visual markers highlight when projected levels cross your configured sleep threshold. The app aims to be usable for people who prefer clean, functional displays rather than dense dashboards, and control labels and tap targets are sized to support one-handed use on phones.

Performance, privacy, and offline use

Designed as a compact tool, Stim Check performs calculations locally to keep responsiveness high and reduce permission needs. Because core features are based on simple math applied to user-provided inputs, the app remains snappy on a wide range of devices and does not require a continuous network connection to show current estimates or edit recent entries. This approach keeps the experience lightweight and focused on immediate decision-making rather than background sync or cloud features.

Limitations and beta status

Currently in public beta, Stim Check may receive interface updates and occasional fixes as the developers refine behavior and address reports. It is focused specifically on caffeine tracking and does not monitor sleep stages, heart rate, or other health metrics. The app provides estimates useful for planning but is not a substitute for professional medical advice; people with caffeine sensitivity, pregnancy, or certain medical conditions should consult a clinician before changing intake based on app estimates.

Who benefits most

Stim Check is useful for athletes tuning pre-workout timing, shift workers managing stimulant timing around sleep windows, students balancing study and sleep, and anyone who wants clearer feedback about how long caffeine lingers. Because the app emphasizes quick logging, clear projections, and minimal overhead, it fits daily routines and can become a simple habit that improves timing decisions and reduces unintended late-night stimulation.