Following Routes and collecting Zygarde Cells (Mateo's Gift Exchange)

Following a route

1. Open the "Routes" tab in the "Nearby" menu on the map and pick a route near you.
2. Tap Follow and walk along the path to the end point.
3. When you finish, you get that route's Route Badge.

From Trainer level 37, you can make your own routes and submit them for review (How to level up fast).

Mateo and the Gift Exchange

• Researcher Mateo may be waiting with a Gift near a route's end point. He isn't always there.
• Talk to him to pick one of the Gifts you collected at a route's start or end point or at nearby PokéStops and exchange it. You receive a Gift and Postcard sent by another Trainer.
• You can do the Gift Exchange once a day (Sending gifts to friends).

Zygarde Cells

You can meet Zygarde in the Special Research story From A to Zygarde, and Cells are stored in the Zygarde Cube.

• Cells appear when you tap the green glow near the end point while walking a route you're walking for the first time that day. You can collect up to 3 a day.
• The Zygarde Cube holds up to 300 Cells.
• Each Forme has different stats, so the site has a separate page for each. Tap a name in the table above to see its 100% CP and recommended moves.

Checklist

• Complete a different route every day (Cells and XP)
• Look for Mateo at the end point
• Change to the 50% Forme once you have 50 Cells

Sources

• Pokémon GO official: Routes — route exploration bonuses, creation requirement (level 37), Mateo's Gift Exchange, Zygarde Cube
• Bulbapedia: Zygarde Cell — 3 a day, 300 in the Cube, Cells needed per Forme
• Site data: Cells needed for Forme changes from the Game Master (PokeMiners) evolution settings