Hi, I've tried to download mobile phone chess a few times now with the same result each time......Invalid password! Obviously I'm sure of my password and have checked the spelling and input many times....Can you help??

the problem i had with the password was when i typed it with my cellphone it came out Capitalized, so on here i made my password in Capital and it wasnt invalid there

Tried that..... to no avail unfortunately

I imagine this is probably a bit late for you but I had the same issue and found this post by searching so hopefully helps someone else who searches in future.  

I have recently solved this by simply changing my phones keypad/ keyboard from compact qwerty to full qwerty when typing the password.  Lol this kept me puzzled for months I kept re-installing the chess.com  mobile Java app but it just wouldn't let me type my password until I changed to full qwerty.  Now finally enjoying mobile chess

Which mobile device is it and which app are you using?