DH has his own business which has really taken off in the last two years and he has now got a couple of big contracts where he has to track his time. When invoicing last night it became clear that he hasn't been doing this properly and so he's probably under-invoiced them as a result. We have had a discussion about this. 
As a result he could do with using a good time tracking app that works on his android phone and laptop so he can just tap it when he gets a phonecall, email etc and is dealing with them. Can anyone recommend a simple one. I've started googling and am a bit overwhelmed by all the reviews.