Drone Scene is one of only three safety apps approved by CAA. It’ll let you submit flight reports and covers your flight restrictions. It does 101 other things too, go check it out, there’s a video on the /About page that covers some of it.
I’m not a fan of weather apps, too inaccurate. If several million quids worth of Met Office supercomputer can’t predict the weather on the ground then a £5 quid Android app certainly can’t predict it at 400ft above your head.
You’ll soon get a feel for the weather and know if it’s safe or a risk.