Jam Timer vs Jamzo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Jam Timer
This app provides precise timing control for roller derby officials, offering built-in configurations for various leagues and professional timing features. It's designed for one-handed operation with a clear display and haptic feedback, working completely offline.
- Built-in game configurations
- Professional timing control
- Designed for officials
- Game management features
- Offline operation
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RollTimer: The Professional Jam Timer for Roller Derby Officials Designed specifically for the jam-timer position, RollTimer eliminates the need for traditional stopwatches and provides precise timing control for all roller derby formats. Whether you're officiating WFTDA sanctioned bouts, RDCL tournaments, or OSDA games, RollTimer has the configuration you need. Key Features: Built-in Game Configurations WFTDA standard timing rules RDCL tournament settings OSDA game format Custom configurations for scrimmages and special events Professional Timing Control Precise jam timing with lead jammer call-off Period clock management Lineup time tracking Team and official timeout timers Automatic vibration warnings at configurable intervals Designed for Officials Large buttons for one-handed operation Clear, high-contrast display visible from across the track Haptic feedback for critical timing events Works completely offline - no internet required Game Management Track team scores and timeouts Monitor official reviews remaining Complete game history and statistics Export game data for league records Perfect for: NSO jam timers at sanctioned bouts Tournament directors managing multiple games League officials during practice scrimmages Coaches timing drills and scenarios Referees needing backup timing Why Choose RollTimer: Unlike generic stopwatch apps, RollTimer understands roller derby. Every feature is built around the specific needs of derby timing, from the 30-second lineup to the 2-minute jam clock. The large, accessible interface ensures you can focus on the game, not fumbling with tiny buttons. Trusted by officials across leagues worldwide, RollTimer brings professional-grade timing to your mobile device. Download now and experience the difference purpose-built software makes. Offline Operation: RollTimer works completely offline with no network requirements, perfect for venues with poor connectivity. All game data is stored locally on your device for maximum reliability.
Jamzo
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Jamzo brings together essential tools to support teams and officials during roller derby games. NEW — LINEUP & PENALTY TRACKER Easily track lineups and penalties throughout the game: • Record the skaters participating in each jam • Identify jammers, pivots, and blockers • Assign penalties and track Penalty Box visits • View the game history in real time • Work independently or with another operator on separate devices • Access a complete game recap • Export game data for review or archiving SCOREKEEPER • Record the score jam by jam • Follow the game’s progress in real time • Choose between solo and dual modes • View and export the game recap TIMING TOOLS • Jam Timer: track jams, intervals, and periods • Penalty Timer: time Penalty Box visits • Blocker Timer: manage blocker penalties • Jammer Timer: manage jammer penalties • Dual Timer: use two timers on a single screen TEAM DIRECTORY • Discover roller derby teams • View their city and country • Access their social media pages RULES QUIZ • Test your roller derby knowledge • Choose your difficulty level • Learn and review the rules in a fun way Jamzo features a clear, responsive interface designed to remain easy to use in real game conditions.
Screenshots
Verdict
The clearest difference is price: Jamzo at Free against Jam Timer's $3.99. Jam Timer's advantage is chart position (#188 vs unranked). On ads, in-app purchases, device support and iOS requirement 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
Jamzo is free to download; Jam Timer costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
| Parameter | Jam Timer | Jamzo |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | 1.0 (1 ratings) — better | — |
| Number of ratings | 1 — better | — |
| Update frequency | — | Every 6 weeks |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Best chart rank | #188 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 15.1 — better |
| Further details — not scored | ||
| Size | 19 MB | 44 MB |
| Age rating | 4+ | 17+ |
| Developer | DLY | Charles Robart |
In-app purchases
Jam Timer
No in-app purchases
Jamzo
No in-app purchases









