Moving to AppGlance

The integration takes about five minutes. The part worth planning is everything around it: what happens to the history you already have, and how you convince yourself the new numbers are right before you switch anything off.

Start here: your history does not come with you

Run both at once first

Nothing stops you shipping both SDKs in the same build, and it is the only way to get an honest comparison. Do that for one release cycle. Then compare like for like, and expect the totals to differ, for reasons that are not bugs:

• We count a user as an install, identified by a random UUID kept in the Keychain (Apple) or SharedPreferences (Android). Firebase counts app instances; TelemetryDeck derives an anonymous hash. Reinstall behaviour differs between all three, so "users" will not match.
• Sessions end after five quiet minutes. If your old tool used a different timeout, session counts will differ by construction.
• Debug and Simulator builds do not send by default, so if your old tool did count them, ours will read lower until you ship. That is the intended difference.
• Presence pings and user labels are not events. Heartbeats, user.identify and user.reset are excluded from event counts entirely.

When the shapes of the curves agree, the migration is done. Chasing exact totals is not a good use of your week.

From Firebase Analytics

The call maps almost directly. Firebase's event name becomes the signal; its parameters become metadata.

// Firebase
Analytics.logEvent("purchase_completed", parameters: ["tier": "pro"])

// AppGlance
AppGlance.track("purchase_completed", metadata: ["tier": "pro"])

// Firebase
firebaseAnalytics.logEvent("purchase_completed") { param("tier", "pro") }

// AppGlance
AppGlance.track("purchase_completed", mapOf("tier" to "pro"))

Three differences to plan around:

• You do not need to port screen or session events. Sessions, installs and "active right now" are automatic. Delete your screen_view and session_start plumbing rather than translating it.
• Metadata is strings only, and bounded: 20 keys, keys up to 40 characters, values up to 200. Numeric parameters become strings. This is a deliberate limit, it is what keeps a metadata value from quietly becoming a place personal data ends up.
• There are no audiences, no ad attribution and no BigQuery export. If your Firebase setup leans on those, we are not a replacement for that part and you should say so in your own planning.

From TelemetryDeck

The models are close, because the philosophies are close. A signal is a signal.

// TelemetryDeck
TelemetryDeck.signal("purchase_completed", parameters: ["tier": "pro"])

// AppGlance
AppGlance.track("purchase_completed", metadata: ["tier": "pro"])

The real difference is identity, and it is the reason to switch or not to switch. TelemetryDeck is built so that you can never resolve a signal back to a person. AppGlance keeps a stable per-install id, so you can open a single user and see their sessions in order, and you can call identify to attach your own label to it. If the ability to look at one user is what you want, that is what you are moving for. If you consider that a feature you would rather not have, TelemetryDeck is the better fit and we would rather you stayed there. We wrote that comparison out in full.

Take the chance to fix your event names

A migration is the one moment when renaming events costs nothing, because there is no history to break. Two rules that will save you later:

• Names describe what happened, not what it was worth. purchase_completed with {"tier": "pro"}, never purchase_pro_9_99. A value baked into the name cannot be grouped, filtered or summed, and it means every price change forks your history.
• Never put personal data in either half. Not in the name, not in metadata. No emails, no user ids from your own backend, no free text a user typed. Our privacy label tool assumes you followed this; if you did not, its answers stop being true for your app.

Cut-over checklist

• Both SDKs shipping in one release, numbers compared for a full cycle.
• Old data exported, if you will ever want it.
• Event names reviewed once, while renaming is still free.
• Privacy labels regenerated, your App Store answers change when your SDKs change.
• Old SDK removed, and its key revoked in its own dashboard.