Version 0.5 · decided 5 Oct 2026 · in force from 14 Oct 2026
openAPPindex measures app stores and the apps in them. Whoever pays for that measurement could want it to come out a certain way. This policy says what money can and cannot do here, and how anyone can check.
The rule in one sentence: no money buys a place in the index — and everyone who supports us is named.
Nothing that appears in the index, the dataset or anything else we publish can be bought, by anyone, at any price:
- whether an app is included, how it is described, where it appears or in what order; - anything that works like placement: sponsored listings, "featured" spots, badges, advertising next to the index, affiliate links; - a correction, a removal or a delay; - advance notice of a finding, a preview, or a right to review before publication; - a say in which categories we measure, how we classify apps, or what we sort by.
Anyone — supporter, customer, developer, stranger — can report an error to korrektur@openappindex.org, and every report goes through the same public process. When a correction was requested by someone who supports us, the dated correction notice says so.
Anyone may support openAPPindex on the terms of this policy — individuals, foundations, public bodies and companies, app publishers included.
Why publishers are not excluded: app publishers as a group gain from an index that makes apps findable by what they do and what they cost, rather than by who is already popular. Supporting that is not buying a position in it, and section 1 makes sure it cannot become one. Excluding every publisher would not even be possible: on 24 Sep 2026 the German App Store listed apps from the EU's Publications Office, German federal agencies, Verbraucherzentrale NRW, Stiftung Warentest, Mozilla and the Wikimedia Foundation (iTunes Search API, German storefront).
What we ask of it in return is disclosure, and three limits:
- Support from an app publisher is unearmarked, or tied to a work item already on our public roadmap. It cannot add, drop or prioritise a category, and it is never tied to an app. - Every app a supporter publishes is marked as such on its page in the index: "The provider of this app, or the organisation it belongs to, supports openAPPindex. Details: funding page." A fact next to the other facts; it changes nothing about how the app is measured. - Anyone who asks for something from section 1 is turned down, whoever they are.
The one exclusion: store operators. We accept no money, in-kind support or anything else of value from a company that operates an app store we measure — today Apple and Google — or from any company it controls. They publish apps too, but they are also what the index measures: its findings are about their stores. We look one step through: if Apple or Google is a named funder of the specific programme, prize or fund that would pay us, we do not take that money.
Concentration. No single private supporter (a company, a foundation or an individual) provides more than 25% of a year's income, so no supporter becomes one we cannot afford to lose. App publishers, taken together, provide no more than 25% of a year's income. Public grants are exempt from both caps.
openAPPindex is run by Tim Meyerdierks, who also builds and sells galleybook, a recipe app in the cooking category we measure. The rules for that:
- galleybook is measured by the same published rules as every other app, and its page in the index states that it is built by the person who runs the index. - galleybook gets no data that is not public: no unpublished measurements, no private runs, no early look at a snapshot. Any analysis for galleybook — including its app-store optimisation — runs only on the published dataset and published snapshots, the same files anyone can download. - galleybook's store listing and marketing do not cite openAPPindex, and openAPPindex does not mention galleybook except on its app page and here. - The index's costs are paid by Tim personally and disclosed as such (section 5). Any money from galleybook as a business would be listed like any other supporter.
- Grants and public funding, when the terms give the funder none of the rights in section 1. A funder may agree a work plan and milestones with us; it may not review, approve, delay or keep confidential what we find. We do not sign agreements that would allow it. - Prizes and fellowships count as support and follow the same rules. - Support from organisations — every organisation is named, whatever the amount. - Donations from individuals — anyone who gives €1,000 or more in a calendar year is named, with their consent, or the gift is returned. - Earned income: we sell results, never placement. Services built on the index — bulk data, alerts, reports, API access — are sold on a public price list, on the same terms for everyone, app publishers included. The facts stay open under CC BY 4.0; what is sold is convenience, format or timeliness, never exclusive facts and never influence. Every organisation that buys is named. - In-kind support counts as support. Credits, sponsored plans or services given to us on application are listed at their stated value. Free plans that anyone can use on the same terms are not support; we list the ones we depend on.
A funding page lists every supporter: name, amount, period, purpose, and the date agreed, added within 30 days of an agreement. Once a year we publish totals by type of source — including the share that came from app publishers — the share of the largest single source, and the amount Tim contributed personally.
Grant applications are listed once decided, awarded or declined, with the date, the funder and the amount requested.
Changes are dated, versioned and published as a diff before they take effect. No change applies retroactively. An offer that does not fit these rules is declined, or the rules are changed in public first — there are no private exceptions.
When openAPPindex becomes a non-profit company, this policy moves into its articles of association.
None. All costs are paid by Tim Meyerdierks personally.
Free plans we depend on, available to anyone on the same terms: GitHub (Microsoft) for code hosting; Cloudflare for serving the site, DNS and email forwarding.