Besides buying the template you need some basic web skills in order to customize it. Nothing too fancy HTML/CSS will do just fine and a little bit of image editing. You can always hire a web designer to help with the customization work while you provide the template and the content that is the most important.
Are you looking for ways to grow the user base for your mobile application? Then you have arrived at the right place. Here you will find a curated collection of landing page HTML templates that will help you build an engaging online presentation for your mobile app and convince visitors to become loyal paying users.