The majority of your parents (if not all) will be online, so online promotion is an ideal way to reach them to download OurSchoolsApp.
Social Media
If your school has a Twitter, Facebook or Instagram account, regularly post details about OurSchoolsApp on there. Encourage parents to retweet and share your posts to grow the audience. Ensure you include a call to action - i.e. don't just tell them about OurSchoolsApp - actually urge them to download it.
See our Resources section to download social media graphics which you can use for your own channels.
If you routinely communicate with parents via email, be sure to include information about OurSchoolsApp by email. We would advise this is done on a regular basis given the sheer number of emails that most people receive daily - it could easily be missed.
A sample email (to save you the time of writing it yourself) is available for download in our Resources section.
(Incidentally, if you don't already use a mass email platform for communicating with parents, Call Parents is a fantastic solution)
Website
Your website is likely to be your parents' first port of call when trying to find out information about school. Just like on your social media channels, include an advert/banner on your home page, informing parents about OurSchoolsApp and how they can download it.
Why not set a visible target/counter of the number of downloads you're hoping to achieve, and keep updating it as your downloads increase, to act as a motivator and incentive for parents.