Gist for https://github.com/twolf611/Xamarin.Forms-SQLiteExample

SQLiteService.cs

using System;
using System.IO;
using SQLite;
using Xamarin.Forms;

[assembly: Dependency(typeof(SQLiteExample.Droid.SQLiteService))]
namespace SQLiteExample.Droid {
  public class SQLiteService : ISQLiteService {
    string GetPath(string databaseName) {
      if (string.IsNullOrWhiteSpace(databaseName)) {
        throw new ArgumentException("Invalid database name", nameof(databaseName));
      }
      var sqliteFilename = $"{databaseName}.db3";
      var documentsPath = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
      var path = Path.Combine(documentsPath, sqliteFilename);
      return path;
    }

    public SQLiteConnection GetConnection(string databaseName) {
      return new SQLiteConnection(GetPath(databaseName));
    }

    public long GetSize(string databaseName) {
      var fileInfo = new FileInfo(GetPath(databaseName));
      return fileInfo != null ? fileInfo.Length : 0;
    }
  }
}