I had been looking for something for hangboard interval training without the need to use chalky fingers on my device. I looked through a couple of stopwatches and interval timers when I came across this app. You can create your own training programme or use one of the templates to start off with. When you start training, a voice will tell you when to hang/do pull ups. And it has a picture of the hangboard youre using so you can see which pockets to use for each hang. Its pretty useful!
Littlelambot about Boulder Trainer, v3.0.1