I have these on my Android phone, but they may be available on Apple and Windows products.
If you haven't got it already, Google Drive is a good one to have. If you have documents that you want to look at at home, on your tablet, or on your mobile, you can store and write them on there. Any changes you make are then updated on all devices you have. Only issue is that it is entirely online - you can't even edit a document or start a new one to upload later if you aren't connected to the internet.
I also have the Emergency Information: ICE app on my phone. It is a little button that appears on your lock screen and gives emergency services details in case of an emergency (such as who to contact and any allergies you may have). I think it cost me £1.69 or something like that, but worth it in my opinion.
I was also about to recommend Spaceteam for Apple users, but it now finally on Android... I will download later and update.