If you’re a little like me and sometimes need to think about something else than the next problem in your build tasks you might look to browse online. If you like to make this time a little more targeted then I recommend that you have a look into HackerRank.
It’s a small but well organised code challenge based app/community. I have only looked into the Java based areas but it does look quite good. The challenges being laid out in a descriptive manner, the objective to the challenges are clear but the instructions do not give anything away to how to achieve the solution.
I’ve spent many hours on websites such as Codecademy in the past. HackerRank doesn’t seem to focus on the tutoring compared to Codecademy, instead it lets you test what you already know and by doing so makes you highlight areas which you are not as sharp with as you originally think.