BlendPic is the best and easy to use app for creating the best double exposure effects and collages. 

With this app, you can combine two images and create a new one, and you can choose from a variety of different overlays. It's easy to use and can be done in a couple of seconds. 

You can choose from a variety of different quotes, images, and other overlays to add to your photos.

It's a free app and there are no charges to use it.

You can choose to use the free version or the paid version.

The free version has a limit on the number of pictures you can combine and the number of pictures you can choose to include in your collage.

The paid version has no limits and allows you to use more pictures.