Create custom countdown patterns exactly the way you like.

After trying several apps and failing to find one that suited all my needs, I decided to write Complex Timer.
Initially developed for sport climbing training: intermittend dead-hangs, fingerboard, or strength-endurance methods, it is very useful if you perform sport training methods like HIIT (high intensity interval training), cross fit, cross training, running, tabata, etc.., Also to control your pauses at work, while studying or rehearsing an exam and for cooking.

Features:
- Backup and restore your sessions
- Copy a session to use it as a template for a new one
- Group countdowns that repeat several times
- Nest a group inside another one to create complex patterns
- Move countdowns or whole groups up/down or even inside/outside groups
- Copy countdowns or groups to save time
- Goup and countdown descriptions are customizable
- Set the type of alarm that will be played before a countdown starts, so that you know if a pause or a work segment comes next
- Set an alarm to warn you before the time is up
- Choose among 9 different colors for each countdown
- Skip any particular repetition(s)
- Choose whether the session will pause when a countdown ends
- Skip backward/forward while running a session
- Keep the screen on while running a session
- See the complete session in list form to have a visual reference of what it's going to look like, and use it to skip to any particular countdown
- Run, pause and reset the session from the lockscreen notification
- Receive an alarm that indicates the whole session has ended
- Maximize the counter for better readability and use basic control gestures
- Custom notifications: choose your own sounds from your device's storage, or mute any of them
- Custom relative volume: when listening to music while using the app, you can lower the notifications volume relative to the music volume
- The total work time for each Session is displayed in the main screen
- Option to vibrate instead of/in addition to playing a sound. Good for very noisy or very quiet environments
- Add random variation to any Countdown inside the limits you establish.
- Navigate to any desired Countdown using a Seek Bar.
- Skip back/forward to any moment in the current Countdown, even while running, using a Seek Bar
- Mute the nofications while running a Session
- Use text-to-speech to know how much time is left or hear the next Countdown description in your own language (contact me if you want your language to be supported)
- Share one or more Sessions with other users via email, instant messaging, etc.

Permissions: it needs Storage permission if you want to backup and restore your sessions.