Castle is the #95 ranked security & compliance app on Slack, with a free plan available, as of Jul 28, 2026.
AppRanks data: Castle ranks #95 in Security & Compliance on Slack Marketplace, placing it in the top 42% of that category.
AppRanks verdict
Generated from live marketplace data — refreshed daily
Castle is a newly-listed Slack app with a limited review volume. It is listed in the Security & Compliance category on Slack Marketplace, which AppRanks treats as the canonical taxonomy node for ranking and competitor comparison. no published reviews yet means feature claims are unverified by the wider merchant base. Without a published review base, the only fit-signal available is the developer's own documentation plus the marketplace's listing-quality audit (linked below). The free tier lets you trial the entry feature set without committing a payment method. AppRanks tracks rating, review count, pricing tier, and category position daily — the figures on this page reflect the most recent scrape from the canonical Slack Marketplace listing.
Pros
- +Free tier available — no card required to evaluate
Cons
- −No public reviews yet — fit and reliability are unverified
Looking to switch from Castle?
See Castle's alternatives ranked by audit score, rating, and review velocity.
About Castle
How Castle works
Castle can send notifications to Slack channels whenever items are added to a List. This means that your team can get real time notifications whenever a condition of your choice is applied, and have it be based on any type of entity, such as User, IP or email domain. Slack notifications are a great way of monitoring the impact of Policies before deciding to take action, e.g. to highlight users sharing accounts. Useful links: Pricing - https://castle.io/pricing Privacy - https://castle.io/privacy
Category rankings
As of Aug 3, 2026- Security & Compliance#95of 230Top 42%
- Analytics#143of 303Top 48%
See 90-day rank history for each category
Track daily rank changes, category shifts, and position volatility.
Competitors & alternatives
Castle doesn't have curated competitor matchups yet. Other tracked security & compliance apps on Slack:
Where Castle stands in the Security & Compliance category
Castle ranks #95 of 230 apps in the Security & Compliance category, placing it in the top 42% of the listing.
Frequently asked questions
What is Castle?
Castle is an app for Slack. It is published on Slack Marketplace and tracked by AppRanks, and AppRanks has been tracking its public marketplace data on the refresh cadence published in our methodology. It is listed under the Security & Compliance category on AppRanks, where you can see its current category position, review-velocity trend, and how it compares against the top alternatives in the same space.
Is Castle free?
Castle does not offer a permanent free plan on Slack. Pricing starts at Paid, with a free trial. Trial availability and exact billing terms are mirrored from the live Slack listing and may change between refresh cycles, so always confirm the headline price on the source marketplace before installing.
Who uses Castle?
Castle is actively installed across Slack stores tracked by AppRanks. Its review base is still building, which usually maps to early-stage merchants and stores piloting a new workflow. It is part of the Security & Compliance category on Slack.
Where does Castle rank on Slack?
Castle currently sits at position #95 in the Security & Compliance category on Slack. That places it in the top 41% of 230 apps tracked in the same category. Category positions are read from the live marketplace ranking and refresh on each scrape, so the number you see here reflects the most recent crawl rather than a long-running average.