Adobe announced its plans to bring a full Photoshop app to the iPad this week, and the news was received with mixed reactions. While some people are looking forward to having a more robust version of Photoshop on their Apple tablets, others were unmoved by the news, having already adopted other editing tools for the iPad. Apps including the Affinity suite and Procreate have already established themselves as reliable (if not better) Photoshop alternatives, and, most importantly, they can be bought through a one-time purchase rather than a subscription. While developers say they welcome the competition, history indicates that their reliance on one-off purchases could mean they’ll struggle to survive in the long term.

Affinity Photo and Designer offer many of the same core tools as Photoshop, and they can open PSD files and synchronize them between their iPad and desktop apps. Both are available for a one-time cost of $20, a more affordable alternative to the desktop version of Photoshop, which is available through a Creative Cloud subscription plan that starts at $10 a month. “Obviously Adobe have the vast majority of the creative professional market, so for them to promote workflows like this can only be a good thing for us, and validates what we have been doing with Affinity,” Ashley Hewson, managing director at Serif, which makes Affinity Photo and Designer, tells The Verge.

Though having the ability to work on shared PSDs across devices is one of Affinity’s best features, what Adobe’s promising with Cloud PSDs goes even further. The new file format will sync every edit to the cloud, not just the most recent save. This will give you access to the file’s entire history on whatever device you open it on, as long as it has been uploaded to the Creative Cloud.

Hewson predicts that Adobe may eventually develop its Cloud PSD format into a single, consolidated file format, a system the Affinity suite already implements. “What will be more interesting is where they take things with Illustrator and InDesign. A critical part of our offering is not only having a single file format between mobile and desktop, but also exactly the same file format between Affinity Photo, Affinity Designer and Affinity Publisher,” Hewson says.

James Cuda, CEO of Savage, the company behind Procreate, predicted that the new Photoshop app would only attract more artists to the iPad. “It’s great to see Adobe finally take iPad seriously,” he says. Procreate has been developed exclusively for the iPad since the tablet launched, and it’s clear to see its influence on Adobe’s rethinking of Photoshop for the iPad and in its upcoming illustration app, Project Gemini. “For instance, the Selection tool they demonstrated is a carbon copy of the Procreate selection tool we developed years ago,“ Cuda says.

Like many artists who have switched over to Procreate and Affinity, Cuda isn’t a fan of Adobe’s subscription model. “We’ve opted to keep Procreate as a one-off purchase, because we believe artists should completely own the tools they use to create,” he says.

For creators, it’s a nice idea — or at least a cheap one. But it can also make life much harder for developers. In recent years, makers of productivity apps have largely switched to subscription models, after finding that one-off purchases can rarely sustain a business over the long term. Among those businesses is Adobe, which moved away from selling boxed software in favor of its Creative Cloud subscription model. The company saw revenue increase 44 percent in its first four years after adopting subscriptions. Apple now encourages developers to generate revenue through subscriptions.

Procreate’s $10 pricing is appealing to professionals and amateurs alike. But anyone who already pays for a Creative Cloud subscription will get Photoshop on the iPad for free. For now, the developers behind Affinity and Procreate say they aren’t worried. The arrival of a giant competitor doesn’t automatically mean it will be successful, as Facebook learned the first half-dozen times it cloned Snapchat. But Facebook eventually caught up to Snap when it added a Stories feature to Instagram. Over time, Photoshop’s arrival on the iPad could limit the audience of apps like Procreate to a smaller number of amateurs who want to dabble with creative tools without having to subscribe. Music streaming service Rdio certainly didn’t seem threatened when it tweeted, “Welcome Apple. Seriously.” in response to the launch of Apple Music in 2015. But the app ultimately folded just a couple months later.