Google has decided to retire Picasa. When they came out with Google Photos, they feel it is smarter and a better way to upload and share your photos. Combining mobile and desktop.
Picasa has been a well-known photo organizer and editor. Google Photos has more success with it's newer storage and sharing.
Picasa Web Albums
For those who use Picasa, the easiest way to access your photos is to log into Google Photos. All of your photos and videos will be there.
For those who do not wish to use Google Photos, they will be creating a new place to access your Picasa Web albums. You can still view, download or delete your Picasa Web albums, you will not be able to create, organize or edit albums. This type of editing can be done with Google Photos.
None of this is happening today—if you have a Picasa Web Album you can keep using it as normal. They will start rolling out these changes on May 1, 2016.
They will not be supporting Picasa Desktop Application. It will continue to work, however there will be no more updates.
They are focusing their efforts on Google Photos, an online photo management system.
It can sync photos across your many devices, such as computer, laptop, tablets and phones.
I know many people are no happy about these changes.
It seems everytime we turn around, more things are going to the cloud.
I think Google Photos is a decent idea, but it isn't as sufficient as Picasa.
Google Photos also doesn't have the editing features that Picasa had. It has three editing tools plus 14 filters. It also doesn't have watermarking.
You might want to consider other photo editing programs.
LUNAPIC also offer other editing choices.
and don't forget PICMONKEY