Why is this a threefold repetition draw? I'm relatively new, so sorry if this is obvious. Recently played a game on my phone chess app where the option popped up that I could claim a threefold repetition draw. I hadn't known about this rule. Researching I found this: https://en.wikipedia.org/wiki/Threefold_repetition#The_rule

But I can't figure out the three positions that were exactly the same at any point. Can someone point it out to me? I can find three where I (as black) repeat positions moving around my rook at the end, but the white pieces seem to be in different places when this happens, specifically the white king.

Thanks for the help! Below is a link to the game analysis, plus the full pgn notation.

Game upload:

http://en.lichess.org/CYvX2RlR

Full notes:

[fen ""]
1. d4 d5
2. Nc3 Nf6
3. Bg5 Bf5
4. Bxf6 exf6
5. e3 a6
6. Bd3 Qd7
7. e4 dxe4
8. Bxe4 c6
9. Bxf5 Qxf5
10. d5 Bc5
11. Qe2+ Qe5
12. Qxe5+ fxe5
13. O-O-O Bxf2
14. d6 Nd7
15. Nf3 O-O
16. Rhf1 Be3+
17. Kb1 Rad8
18. Rfe1 Bf4
19. g3 Bh6
20. Nxe5 Nxe5
21. Rxe5 Rd7
22. Re7 Rfd8
23. Rxd7 Rxd7
24. g4 Bf4
25. Ne4 b6
26. c4 Bxh2
27. Re1 Rd8
28. Rd1 Rd7
29. g5 Bf4
30. Kc2 h5
31. gxh6 Bxh6
32. b4 Bf4
33. c5 b5
34. Rg1 Kf8
35. Rg4 Be5
36. Kd3 f5
37. Rg5 fxe4+
38. Kxe4 Bf6
39. Rf5 Rf7
40. Rf3 Ke8
41. Rh3 Rf8
42. Ra3 g5
43. Rxa6 Bd8
44. Ke5 Kd7
45. Ra7+ Kc8
46. Ke6 Rf6+
47. Ke5 g4
48. Ra8+ Kd7
49. Ra7+ Kc8
50. Ra8+ Kd7
51. Ra7+ Ke8
52. Rg7 Rf2
53. Rxg4 Rxa2
54. Ke6 Re2+
55. Kf5 Kf7
56. Rg3 Rf2+
57. Ke4 Rb2
58. Ke5 Bf6+
59. Kf5 Rf2+
60. Ke4 Rh2
61. Ra3 Ke6
62. Ra6 Rh4+
63. Kd3 Kd5
64. Ra7 Rxb4
65. Rf7 Rd4+
66. Ke2 Rf4
67. d7 Ke6
68. Rxf6+ Rxf6
69. d8=Q b4
70. Qd6+ Kf5
71. Qb8 Re6+
72. Kd3 Re4
73. Qc8+ Re6
74. Kc4 b3
75. Kxb3 Ke5
76. Kc4 Kf6
77. Kd4 Kf7
78. Kc4 Re4+
79. Kb3 Re6
80. Ka4 Kf6
81. Ka5
The position after 47.… g4, 49.… Kc8 could have been repeated with 51.… Kc8. 

Because you have to claim threefold repetition before you make the move 51.…Kc8, producing the same position on the board, this would have been a sensible point for a popup dialog.