Rheo

Rheo is a mobile experimentation platform for changing app flows without waiting for App Store reviews. Teams use its visual canvas to build onboarding, paywall, win-back, and upsell paths with branches and targeting. They can compare holdouts and variants in flow structure, copy, and timing, then review conversion and revenue. Rheo says its flow layouts, animations, inputs, and system moments render natively on iOS and Android. React Native is supported; Swift, Flutter, and Kotlin are listed as coming soon. After SDK integration, teams can publish flows for the app to pick up. The dashboard tracks flow completion and provides funnel and cohort views. Rheo Engage supports email broadcasts and automations through a customer’s SES, Resend, Postmark, or SendGrid account. The free plan includes 400 MAU and no experiments. Grow costs $49.99/mo and includes up to two active experiments. Exceeding the included MAU quota pauses the SDK until the next month or a plan upgrade.

Rheo combines flow building, experimentation, and analytics in a mobile-focused platform. Check the MAU limits and supported SDKs against your app needs before choosing a plan.

Rheo suits mobile app teams that want to manage and measure changes to in-app flows. Its homepage describes indie developers as an audience, while its plans also address growth teams and enterprise customers.

Overview

Rheo is a mobile experimentation platform for teams that want to shape and test in-app journeys without waiting for App Store reviews. It best suits indie developers and growth teams iterating on onboarding, paywalls, and related flows. Its combination of native rendering and flow experiments is compelling, but the MAU caps and React Native-only supported SDK make plan fit important.

Key features

A visual canvas lets teams build onboarding, paywall, win-back, and upsell paths, with branching and targeting. That puts several common conversion journeys in one workflow; interactive prototypes, templates, and version history add useful support for developing and revising them.

Teams can compare flow structures, copy, and timing using variants and holdouts, then review conversion and revenue. The dashboard also offers flow-completion measures, funnels, and cohort views. These tools connect experimentation to outcomes, though the free plan includes no experiments, so teams need a paid plan to test variants.

Rheo says its inputs, layouts, animations, and system moments render natively on iOS and Android rather than in a WebView. After SDK integration, teams publish flows from the canvas for the SDK to pick up immediately. React Native is supported; Swift, Flutter, and Kotlin are marked as coming soon, making the current SDK support a meaningful constraint for teams using those native stacks.

Named integrations include RevenueCat, AppsFlyer, Adjust, and Superwall. The developer guide describes RevenueCat and Superwall paywall nodes and AppsFlyer attribution. Rheo Engage supports broadcasts and automations through a customer's own SES, Resend, Postmark, or SendGrid account; that flexibility comes with the requirement to use and manage an external email account.

Rheo says it uses administrative, technical, and organizational measures to protect information, but does not guarantee absolute security. It says it does not sell personal information or store full payment card numbers. Its authentication guide says OAuth tokens and passwords stay with the host app and are omitted from Rheo terminal snapshots and analytics field maps.

Pricing

The free Indie plan is billed Free and includes one app, one channel per environment, 400 MAU, one seat, one active automation, and 2,000 marketing emails per month. It has no experiments. Email sending pauses after the monthly allowance, and exceeding the MAU quota pauses the SDK until the next month or a plan upgrade. That makes Indie a narrow starting point, not a reliable fit for growing usage or teams that need experimentation.

Grow costs $49.99 /mo and covers three apps, three channels per environment, 10,000 MAU, five seats, and up to two active experiments. It includes 50,000 marketing emails per month, then charges $1 per 1,000; additional MAU costs $0.01 per MAU per month. This is the entry paid tier for small teams that need to test flows, but its quotas can add costs as audience and email volume rise.

Scale costs $199 /mo and raises the limits to 10 apps, 10 channels per environment, 100,000 MAU, 25 seats, and up to five active experiments. Its 500,000 monthly marketing emails are followed by a $1-per-1,000 charge, and additional MAU remains $0.01 per MAU per month. It suits larger teams that need more seats and experiment capacity, though the same usage-based MAU and email charges still matter.

Enterprise has custom pricing, with unlimited apps, channels, and experiments; MAU and seats are set by contract. It also includes implementation support, SSO, and a custom SLA, making it the plan for organizations that need those provisions rather than fixed self-serve limits.

Platforms

Rheo supports iOS, Android, and React Native. Teams building with Swift, Flutter, or Kotlin should wait for the promised SDK support or choose a platform that fits their current stack.

Who it's for

Rheo is strongest for mobile teams that iterate frequently on onboarding, paywalls, win-back, or upsell journeys and can use React Native or its supported iOS and Android SDKs. Indie developers can begin on the free tier, while growth teams can pay for experiments and higher MAU limits. It is a weaker fit for teams that need experiments at no cost, exceed the included MAU allowance, or depend on a not-yet-supported SDK.

Pros and cons

• Pros: Native iOS and Android flow rendering avoids a WebView-based presentation, and publishing through the SDK is designed to avoid waiting for App Store reviews.
• Pros: Holdouts, variants, and funnel and cohort views let teams compare changes and examine flow outcomes.
• Pros: Grow and Scale spell out app, seat, experiment, and MAU allowances, so teams can compare capacity before upgrading.
• Cons: Indie offers no experiments, and its 400-MAU cap can pause the SDK when exceeded.
• Cons: Swift, Flutter, and Kotlin support is not yet available, limiting options for teams using those stacks.
• Cons: Paid plans charge for additional MAU, while email sending pauses on Indie and incurs overage charges on Grow and Scale.

Alternatives

For a broader selection of tools, browse User Flow Software. Choose Marvel instead if you want a general prototyping option with a free plan and free trial; its Free plan is limited to one user and one project, while Pro is $12.00 per month, billed yearly, for one user and unlimited projects. FlowSnap is another free-plan option, with up to three projects and PNG export carrying a watermark.

Sketchflow.ai is a freemium alternative for Android, iOS, and web. Software Ideas Modeler may suit teams working on Linux, macOS, or Windows who need UML and basic diagrams; its Standard plan is free for non-commercial use. BenchCanvas is a freemium web and extension alternative.

Cairn suits macOS users who want scenario mapping: its free plan allows one project and up to two scenarios, with no file import or export. EVONX is a web-based freemium option. Figr is another freemium choice, with web, API, and extension platforms.

Verdict

Choose Rheo if your mobile team needs to build and measure in-app flows, values native rendering, and can work within its SDK and MAU limits. Its clearest advantage is the link between flow design, experiments, and conversion analytics; its clearest reason to look elsewhere is the lack of experiments on the free plan and limited current SDK coverage.