How to grow an app with WhatsApp

In the latest Nigeria Smartphone Study by Orange and KPMG, WhatsApp was on 95% of the smartphones they looked at, across 13,251 people in 12 Nigerian cities. That was more than any other app. Telegram was on 27%. It's light on data and works on cheap Android phones, which helps explain why.¹

So when someone in Ibadan wants to tell a friend about your app, they won't email the link. They'll forward it on WhatsApp. Your job is to make that forward easy, and to have something worth forwarding.

Download WhatsApp Business and use a number you'll keep for years, not your personal line. Fill in the profile with your logo, a one-line description, your hours and the app's link.

Then set the greeting message. It goes out automatically when someone messages you for the first time. Add an away message for nights and weekends, so people know when you'll reply. Quick replies save you typing the same answer forty times, and labels let you mark chats as “new user”, “bug” or “wants to pay”.²

A wa.me link opens a chat with you straight away. Nobody has to save your number first. To make yours, write your number with 234 in place of the first zero and no plus sign, so 0803 123 4567 becomes wa.me/2348031234567. If you like, the link can also carry a starter message, so the chat opens with “Hi, I have a question about the app” already typed.³

Where does it go? Your website footer. The help screen inside the app. Your Instagram and X bios. A printed QR code on the table when you demo at a meetup in Yaba.² Anyone who taps it has decided to talk to you, so label the chat and keep their number.

Status updates disappear after 24 hours, and the people who see yours are mostly people who saved your number. Treat it as a small, warm audience. Post a 20-second screen recording of the new feature. Share a nice message a user sent, after asking them. Or just write “Fixed the login bug three of you told me about. Thank you.”

Leave the designed flyers for someone else. Your aunty will scroll past an advert, but she'll stop to watch you show off something you built.

A broadcast list lets you send one message to a lot of people at once. Each person gets it in a private chat with you, as if you'd typed it just for them, and if they reply, only you see it. Two limits apply. You can put up to 256 contacts on a list, and the message only reaches people who have your number saved.⁴

The second limit helps you. Someone who deleted your number won't get your messages, so you aren't bothering them. Keep broadcasts for news people on the list would ask about anyway, like a new version, a price change or a two-question survey, and send one a week at most.

Groups are for conversation. They can hold up to 1,024 people,⁵ but a group of 40 active users who answer each other's questions is worth more than 900 who muted it on day one. Make one for your testers or your most active users, and stay in it.

A community puts several groups under one roof, with an announcement group where admins can reach everyone at once. You can give up to 20 people community admin roles.⁶ If your app serves different cities or different kinds of users, one community with a group for each keeps things tidy.

Channels work differently. Only you post. People who follow can react with an emoji, but they can't write back. Your number stays hidden from followers, and theirs from you. WhatsApp lists channels in a directory filtered by country, and it keeps each update on its servers for up to 30 days.^{7, 8} For release notes and news from an app that's growing, a channel beats a noisy group, and people can follow it quietly.

WhatsApp bans accounts it believes are sending spam or scams.⁹ It also looks at how people react to you. Its own advice to businesses says that sending too many promotional messages makes people more likely to block or report you, and that blocks can lead WhatsApp to limit who you can reach.¹⁰

The usual mistakes are easy to name. Adding people to a group without asking. Buying a list of numbers. Pasting the same advert into every estate and church group you belong to. Sending a broadcast every day. Each one leads to blocks and reports, and enough of them can cost you the number you spent months building up.

Keep it to people who said yes, make leaving easy, and when someone asks you to stop, stop. That is most of the rulebook.

On Prow: Posting your app on Prow is free. Your project page gives people somewhere to try it, follow it and leave feedback, and you can post updates as you ship. Share that page on your status or your channel when you post something new, so people who see it can follow along.

• You're on WhatsApp Business with a number you'll keep.
• Your profile, greeting and away messages are set up.
• Your wa.me link is on your site, your app and your bios.
• Your status shows real progress, not adverts.
• Broadcasts go only to people who saved your number, once a week at most.
• Groups are small and active, and a channel carries your updates.
• You never add strangers to groups or message people who didn't ask.