Hello Otatade Okojie here you've just completed your paid ios App congrats. First of all just remember the old adage content is always king. The more content you provide that's of value, the more the algorithm on Google or any other platform heightens your profile. Great ways to promote your paid ios App is social media articles. Research Popular articles in your niche linked to your app, what headlines, hooks and content are going viral, can you create your own content capitalise on hook and sneak in a picture of your app.
With cool headlines?
How about? Hottest new apps sneak attack on the Market
Hot new app blowing consumers away
Hot app fueling hot gossip
Hot new app about to send the internet into a tail spin
Has Facebook met new competition?
Money Markets meet cash ready app?

Also you can write how to columns and tutorials on a freelance Magazine. Articles on how to design an app, step by steps, consistently recommending your app, keep a data capture form, and have people's info to sign them up freemium to your app. So you get their data , they are trialing the app for 30 days, 10 days, or so, yet either way, you still have their info so incase they forget, you have a way to cash in.

Have a newsletter, the newsletter has the same impact. To deliver a stream of content to inspire them to get familiar,get comfortable,allow you to capture their data on data capture forms, so you can either market multiple products to them, or get them on Freemium.

Share the app through your social media content,post the link in comments,groups, webinar groups, any groups you can. Do paid advertising.
Do a podcast a YouTube video
Go for viral content
Go for consistency
Request shares,ask familiar contacts like family, friends, colleagues to share with 5 to 7 people. Have each person share with 5 people.
Do marketing campaigns
Get influencers involved and if your not too cash strapped go for a digital marketing company.