For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Percolator - Percolator: the always fun, supremely unique photo app that is sure to surprise you! FEATURES:
Dropbox - Online Sync and File Sharing
Mosaic Creator - Mosaic Creator is professional mosaic tool. You can create your own picture mosaic.
Google Drive - Access and sync your files anywhere
WidsMob Montage - Make stunning mosaic photos or montage shape with tiles, which supports both JPEG and PNG files.
Mega - Secure File Storage and collaboration