How to create an animation of my webdesign so the client can see the interactivity in the page (including popups, tooltips...) instead of seeing a set of still images? I used to make this task using after effects. Is there another way to do that? Thanks.
I've tried a few, and one of the easiest things I've used was Framer.js. The only thing is that it requires a bit of programming, but then again, you have to learn something with every new software.
This is a bit more difficult that invisionapp, but as you can see from the examples page, it's quite flexible, and you can even use the code for the final product depending on how well-put-together it is.
Another option along the lines of invisionapp is https://marvelapp.com/ Basically it can take your static mockups (psd, png, jpeg, etc) from dropbox and turn them into interactive demos including buttons etc.
It's pretty sweet and free, check it out.
Appdemostore allows you to test their tool and create one demo for free; however, the pricing plans start from $20 and go up to $120. Giveabrief also allows you try the tool for free. If you are ready to invest, you can buy a full license that costs $199.
Both of them are very easy to use, just take your screenshots and add what interaction you need. You can include buttons, icons for pinch, extend etc. Hope it will help you. :)
For a fair few of my projects I've used Zurb Joyride to allow for a in-page tour for the user, as to not draw them too far from the content at hand.