Tessella0.6.5

Draw and examine finite, edge-to-edge tessellations of the plane by placing regular or irregular polygons on an interactive canvas. Tessella is an open-source editor for Android users who want to create, view, and manipulate polygon tilings while exploring their geometry. Add shapes from a palette or place one against an existing boundary edge; each addition is checked automatically so the construction remains a valid edge-to-edge tessellation.

Editing tools can erase individual vertices, edges, or polygons, insert elements in an interior region, and extend a tiling with Add Copy. Add Copy welds a transformed copy onto the existing construction using translation, rotation, reflection, or glide reflection, with snapping to exact anchors. Select elements by clicking, colour, or shape, then change their appearance with the built-in colour picker, while panning, zooming, and rotating the canvas provides different views for inspection. Finished tessellations can be exported as SVG or DOT files.

The Android edition is a thin WebView wrapper around the same client-side editor offered on the web and as a progressive web app; processing takes place on the device, with no network access, accounts, or trackers. It belongs to the Photo & Graphics category, uses Universal architecture, and requires Android 10 or later.

In version 0.6.5, the uniformity overlay handles incomplete patches more clearly: when exact symmetry classes cannot be defined, vertices are coloured according to the symmetry of the drawn patch, and a single polygon appears as one obvious class. The summary also identifies the measure used, preventing counts from different tilings from being confused.