To use this planner you need to have some kind of pdf annotation app so you could write on the pages and click the tabs. Some of them are free, others cost some money. The most common are GoodNotes, Notability, Xodo and ZoomNotes. You can find them in your App Store or in Google Play if you use android. Apart from that you don’t need anything else to use this planner. A stylus would be useful for writing but you can use text feature of the app and type everything you need. 

If you want the tabs/hyperlinks to be clickable you need to turn off writing features of your pdf annotation app. In Goodnotes 5 you can do it by clicking crossed pen icon on the top right when the planner is open, this button turns editing back on as well. In other apps you can use hand icon for this purpose or other buttons that switch the editing off. 

Yes, if your device has a PDF annotation app: GoodNotes 5 (iOS), Notability (iOS), Xodo (iOS, Android), or others you can open the planner on any devices.

This sometimes can happen if your app isn't updated or if you tried opening zip files of png stickers without unzipping it. Also please make sure you open Goodnotes files (they end with .goodnotes) only in Goodnotes. Also it is better to open the files from the PDF apps and not from the download page or the file system.

You can’t change the design, colors or text of anything, move tabs or other elements. 

Yes, I sell undated planners that can be used many times and each year.

Unfortunately, no. OneNote/Keynote don't support files like this.

Metamoji app doesn’t support hyperlinks so the tabs won’t work unfortunately.

Please make sure you are downloading only the .goodnotes file and not the whole folders from Google Drive as it creates zip archives that can mess up with goodnotes files. You can just download the file that ends with .goodnotes and import it to Goodnotes 5 as shown in the instructions. Also using Google Drive might be easier for downloading. 

Unfortunately, it is a Notability feature that some people find useful. In Notability you don’t have editing and hyperlink modes so you can click the links while writing something. Other apps such as Goodnotes 5 have a special mode for clicking hyperlinks so you don’t have any issues like that. 

In order to copy the stickers you need to use lasso tool. Circle in the middle of a sticker you like, tap and hold the screen, choose Copy, go to your planner, tap the screen and choose Paste.

There is no refund, unfortunately, as digital items are not tangible so you can't return them back.