I have no SD card in my phone. And I would like to know how I can save pictures in a place where I can access them later because I download them on tumblr.
Even if you have no SD card, you can use the apps provided by reputed cloud services to store your data. In order to do this, you have to have at least some amount of memory in your device as you have to download them into your phone before you upload them to cloud services. (There are apps that facilitate remote file downloads1 as well). Some of the best apps out there are listed below.
With those apps, you can save, view/listen, edit and share the files you have, without keeping them in your mobile device.
1Remote file downloading allows you to save the files in somewhere without downloading and re-uploading. All you have to do is to paste the file link in the relevant place.